Search found 5447 matches

by mediatechnology
Sat Jun 23, 2012 6:53 pm
Forum: Build
Topic: Dual Class-A Line and Headphone Output Board Construction Information
Replies: 133
Views: 503620

Re: Dual Class-A Line and Headphone Output Board Documents

Thanks Roger!

What are the details e.g. primary impedance, build-out resistance, Cinemag model etc?
by mediatechnology
Fri Jun 22, 2012 12:53 pm
Forum: Document
Topic: Rare NE5534 IC Die Photo and Internal Schematics
Replies: 5
Views: 51401

Re: Rare NE5534 IC Die Photo

In a current EDN series "Analog Back to the Future" I found an interesting statement regarding the LM318 op amp and the trick used to get a 15 MHz op amp bandwidth in the 1970's: Bob Dobkin, Linear Technology’s co-founder, vice president of engineering, and chief technology officer, spent ...
by mediatechnology
Fri Jun 22, 2012 12:13 pm
Forum: The Peabody Lounge
Topic: Residential Lighting with LEDs: Retrofitting the Pink Ranch
Replies: 149
Views: 406961

LED Lighting Doesn't Attract Bugs

"Another advantage of LED lights: They don’t attract bugs, and here’s why," EDN. Gary Trott, a product development innovator for Cree LED Lighting, noticed that the LR6 down lights installed at the entrance to Cree four years ago had no bugs in them. Color sensitivity in the UV spectrum pl...
by mediatechnology
Wed Jun 20, 2012 3:39 pm
Forum: The Peabody Lounge
Topic: Residential Lighting with LEDs: Retrofitting the Pink Ranch
Replies: 149
Views: 406961

LED Garage and Driveway Security Lighting

Many years ago my Dad retrofitted the garage light covering the driveway with a T3 Halogen fixture. Other than appliance bulbs (refrigerator and vent hood) this was the only "tungsten" incandescent load in the entire house. The T3 150W he had installed (I had never replaced it) had gotten ...
by mediatechnology
Wed Jun 20, 2012 8:49 am
Forum: Pro Audio Design
Topic: musician w electronics project -planning stage
Replies: 12
Views: 22183

Re: musician w electronics project -planning stage

I'm not qualified to post in this thread other than to say it's extremely interesting. Thanks for joining us Phidelity and this contribution. I did do some work in pitch extraction for speech and if you can get a close estimate from the fret board I think the job of estimating the actual pitch would...
by mediatechnology
Wed Jun 20, 2012 8:40 am
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 408977

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

I've returned to this project. A couple of months ago I ripped the whole DC-coupled preamp out by the roots to rebuild the prototype and make some improvements based on what I've learned since 2007. My first area for improvement is the differential offset correction servo. There are two reasons to ...
by mediatechnology
Sat Jun 16, 2012 7:21 pm
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 408977

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

If the phantom caps are sized appropriately for for good Z wrt mic source impedance is the 1/F noise audibly problematic or more of a measurement artifact? I think if they are sized correctly it's more of a measurement artifact. When Cphantom is <22uF I think it may become significant. There's alwa...
by mediatechnology
Fri Jun 15, 2012 7:17 pm
Forum: Build
Topic: Dual Class-A Line and Headphone Output Board Construction Information
Replies: 133
Views: 503620

Re: Dual Class-A Line and Headphone Output Board Documents

I guess the word 'duh' applies here.
I used it, in reference to myself, just yesterday. :D

Proud of it too. I earned it.
by mediatechnology
Fri Jun 15, 2012 5:45 pm
Forum: Build
Topic: Dual Class-A Line and Headphone Output Board Construction Information
Replies: 133
Views: 503620

Re: Dual Class-A Line and Headphone Output Board Documents

Could I flip the output polarity by reversing pins 1 & 8 on the DRV? Thanks Paul. Actually you could just re-define the inputs at the THAT124X calling "-" "+." If there was an inverting stage after the 124X producing gain the resulting double-inversion would give you an in-p...
by mediatechnology
Fri Jun 15, 2012 5:40 pm
Forum: Pro Audio Design
Topic: Old: A Direct-Coupled Input-Capacitorless Active Mic Preamp
Replies: 212
Views: 408977

Re: A Direct-Coupled Input-Capacitorless Active Mic Preamp

There is no reason why circa 2k termination cannot be on the same side of the caps as phantom 6.81k. IIRC Buff used 100k to ground at actual preamp inputs and I vaguely recall some private conversations with him about first order cancellation of input noise current when shunt impedance between + an...